How World War Z Used AI to Build Smarter Zombies

Generally speaking, zombies are dumb. They’re clumsy, single-minded corpses that are constantly in attack mode. But for World War Z, London-based VFX house Moving Picture Company had to make the zombie hoards a little more intelligent.

For the movie’s massive piles of Zs in Jerusalem, the VFX company—one of a handful that worked on World War Z—had to build zombie “agents” that could “act” on their own. The digital creatures, whose movements come from motion-capture performances of people running up nets and falling down ramps, were programmed with a kind of artificial intelligence. Using MPC‘s proprietary crowd-simulation program Alice, each “agent” was given a set of rules, an objective to complete. Then a simulation was run to make them crawl all over each other to achieve that objective.

“All complex crowd shots got layers of hand-animated zombies,” said MPC senior CG supervisor Max Wood. “We’d start off setting the shots up in Alice, our in-house crowd tool, then we’d work out where we wanted to add the additional animation detail.”